The need for and use of a gauge for testing the tension on an elongated flexible element, such as the reach of a belt, are well known, particularly in the automobile industry. Such devices have been developed and are in use, but frequently provide inaccurate results. The inaccuracy arises largely from the fact that at least the inexpensive forms of tension gauges do not allow for variations in thickness of the element being tested, which variations result from wear or irregularities created during the use or construction of the element. For example, existing gauges designed to test fan belts are usually arranged for engaging the belt at three spaced points, the intermediate point being on the opposite side of said belt from the outer points. The gauge is calibrated, when manufactured, for a belt of selected thickness. Thus, if the belt is irregular in size, or is worn, or is otherwise different from the calibrated standard, the indications of the gauge will be inaccurate.
Prior efforts to eliminate this inaccuracy have been fully satisfactorily solved, for example, utilizing the tension gauge disclosed in U.S. Pat. No. 2,996,914. This tension gauge comprises a mechanism in which the indication of tension in the belt is independent of variations in belt thickness. The disclosed structure, however, necessitates a gauge size too large to be used in many applications where space is limited, and is relatively expensive to manufacture, due in part to the mechanical complexity involved in combining the mechanisms that stress the belt and measure the resulting element deflection.
Accordingly, the objects of the present invention include:
1. The provision of a tension gauge for detecting and indicating tension on an elongated flexible element, such as the fan belt of an automotive vehicle, arranged to compensate automatically for variations in the thickness of the element being tested.
2. The provision of a tension gauge as aforesaid which is pleasing in appearance, simple and inexpensive to manufacture, sufficiently small in size to permit use in limited spaces, and sufficiently sturdy in structure to withstand rugged treatment.
3. The provision of a tension gauge as aforesaid, which is foolproof in operation, easily operated with one hand by a garage mechanic, and requires little or no maintenance.